Facing one of the worst rushing defenses in the league and you don't start him? If you're not going to start him with a plus matchup why even hold onto him?
If your mindset was "well, if he blows up on STL then I'll start him going forward" how can you be upset with what he did today?
If your mindset was "well, if he blows up on STL then I'll start him going forward" how can you be upset with what he did today?